There are numerous techniques that are currently used for the treatment of internal body tissues. For example, internal cancerous and non-cancerous tumors can be treated with a variety of techniques such as surgery, radiation and chemotherapy. Each of these techniques offers advantages and disadvantages. One promising non-invasive technology for treating internal body tissues is high intensity focused ultrasound (HIFU). With HIFU, high intensity ultrasound energy is focused at a desired treatment volume. The energy causes tissue destruction via both thermal and mechanical mechanisms.
One of the drawbacks of using HIFU to treat internal body tissues is the time required to treat a given volume of tissue. Currently proposed HIFU procedures may take up to 3 hours to treat a single tumor, which has contributed to poor acceptance of these procedures by both physicians and patients. In addition, the amount of energy required to completely ablate a large volume of tissue results in substantial thermal conduction outward from the ablation volume, which can raise the risk of thermal damage to surrounding healthy tissue.
Given these problems, there is a need for a method of treating internal body tissues in a manner that reduces treatment time, while improving safety, effectiveness and ease of use, and reducing total required energy deposition.